Spacer for nestable containers

ABSTRACT

An improved nestable container arrangement. The arrangement involves the use of a spacer. The spacer is configured to fit between adjacent nested containers to keep a sufficient amount of space between adjacent top ends of the container to prevent the formation of a tight seal between the containers. The spacers are available as an aftermarket device and so can be retro-fitted to virtually any type of nestable containers. The radius of curvature of the spacer is adjustable. The spacers are held in position by a small amount of adhesive.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention concerns nestable or stackable containers. More particularly, the invention is directed to a spacer for nestable containers or vessels.

Description of the Prior Art

Nestable containers made of plastic or impregnated or coated paper, have found wide commercial use. For economical storage and shipment and convenience of handling, such containers are often made with tapered sides and are stored or shipped in a stacked arrangement. Ideally an individual container should be readily separated from the next adjacent container in the stack without the use of much force and, in some situations, merely by the pull of gravity against the weight of the container next in line for removal from the stack.

A common drawback of nested tapered containers is that they tend to become telescopically wedged together, particularly when more than two are stacked so that there is a lot of weight on the bottom containers. Further, nested containers tend to resist ready separation because of a relatively airtight seal, which causes vacuum lock, formed between adjacent nested containers. Such a seal tends to prevent the admission of air between adjacent containers, thus hindering separation.

Attempts to solve the problem generally employ regularly spaced protrusions about the periphery of the top of the container where the airtight seal tends to form. Typical of these arrangements is U.S. Pat. No. 3,484,018 which has a series of annularly spaced projections formed into the upper rim of the bucket to deform the upper portion of a nested bucket to prevent airlock. While this patent may show a new method of solving the airlock problem, it involves the modification of the container itself to perform its function. The present invention and method involves the use of a removable spacer so that any existing container can be retrofitted to avoid the above mentioned stacking problem.

The present invention is directed to a spacer for preventing jamming or vacuum lock between adjacent nested containers. The spacer can be shaped to match the curvature of the nested containers, or laid flat if the container is rectangular. Each spacer has upper and lower abutment surfaces which serve to prevent airlock between adjacent nested containers placed in a vertical stack. A living hinge formed approximately centrally of the spacer allow for conformance to a container or vessel with a wide range of curvatures. An adhesive is used to secure the spacer to the sidewall of the container.

SUMMARY OF THE INVENTION

It is a major object of the invention to provide an improved nestable container arrangement. The arrangement involves the use of a spacer. The spacer is configured to fit between adjacent nested containers to keep a sufficient amount of space between adjacent top ends of the container to prevent the formation of a tight seal between the containers. A living hinge arrangement allows the spacer to bend so as to conform to virtually shape of container. The spacers are available as an aftermarket device and so can be retro-fitted to virtually any type of nestable container. The spacers are held in position by a small amount of adhesive.

It is another object of the invention to provide an improved nestable container arrangement employing a small spacer to prevent vacuum lock of nested containers.

It is another object of the invention to provide an improved nestable container arrangement having a removable small spacing element.

It is a major object of the invention to provide an improved nestable container arrangement where a removable small spacer may be applied to buckets in a range of sizes.

It is another object of the invention to provide an improved nestable container arrangement having a removable small spacing element which can be adhesively but removably applied to containers in a range of sizes.

It is another object of the invention to provide an improved nestable container spacer which can be adjusted to conform to a range of curvatures.

Finally, it is a general goal of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is dependable and fully effective in accomplishing its intended purposes.

These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.

The present invention meets or exceeds all the above objects and goals. Upon further study of the specification and appended claims, further objects and advantages of this invention will become apparent to those skilled in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

Various other objects, features, and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:

FIG. 1 shows a front perspective view of the spacer device of the invention.

FIG. 2 is a plan view of the spacer device of the invention.

FIG. 3 is a rear perspective view of the spacer device of the invention.

FIG. 4 is a side sectional view of the spacer device of the invention.

FIG. 5 shows a series of stacked container using the spacer device of the invention.

FIG. 6A shows an alternative embodiment of the spacer device with adjustable curvature.

FIG. 6B is a representation of the underside of the alternative embodiment illustrating the application of the device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to FIGS. 1-5 the device of the invention, generally indicated by the numeral 10 is shown. It can be seen that the device 10, which is essentially a spacing element or spacer 10 has a generally curved or arcuate shape corresponding to the curved upper edge of the sidewall of 14 a nesting cylindrical container. As shown, the spacer 10 is essentially a curved rectangle having upper 20 and lower 22 abutment surfaces which serve to provide a weight bearing support surface when the spacer 10 is positioned between containers. It should be noted that the arcuate shape of the device 10 is due to the fact that it is intended to be used with a cylindrical container having a circular top opening. If the device 10 is to be used with rectangular containers it would of course be flat, but the functionality would be unchanged as will be explained below.

As can be seen, the device 10 has a unitary construction and thus can be formed using injection molding or similar technique. The device 10 is preferably formed from a high strength rigid plastic or polymer, but any sufficiently strong, rigid material will be effective. While the device 10 is rigid, it is important that compressing the device 10 in the vertical direction (from top to bottom) be made especially difficult as it is essentially the vertical spacing between containers 24 that is being limited by the device 10 and method of the invention. To that end, a lattice of support members 26, 28 are molded into the device 10. Horizontal support members 26 extend laterally from side to side of the device 10 while regularly spaced vertical members 28 extend from the upper 20 to the lower 22 abutment surfaces. The abutment surface 20 engages the lower 23 surface of the annular flange 27 positioned about the opening of most cylindrical containers 24. The device 10 is placed in this position to allow the container 24 to be nested into position within a lower container 24, but prevents full insertion of one container 24 into another. Lower abutment surface 22 engages the upper edge 29 of the lower container 24 and serves to prevent the full insertion of the upper 24 container into the adjacent lower container 24, thereby avoiding vacuum lock or air lock. The device 10 will still be effective even if the container 24 has no flange 27 as the lower abutment surface 22 will come into contact with the top edge 29 of the lower container 24 in a stack of nested containers 24 as will be explained in more detail later. Both the horizontal 26 and vertical 28 members extend from the front 30 to the rear face 32 of the device 10. The vertical members 28 help prevent compression of the device 10 from top to bottom, and this action is greatly aided by horizontal support members 26 as the two form a lattice which strengthens the device 10 against compression in either direction. The use of the lattice structure allows the device 10 to be nearly as strong as a solid block of material but with greatly reduced cost and weight. A centrally positioned indicia panel 34 is formed in the front face 30 of the device, the panel providing space for positioning a product logo or instructional information about the device 10, the indicia panel 34 useful as a push tab when applying the device 10 to a container. A recess 38 is formed in the rear face of the device 10, which recess terminates at panel 34, the recess 38 including sidewall 40. Sidewall 40, support members 26, 28, and panel 34 are all of the same thickness so that during manufacture the cooling or curing time for all portions of the device 10 are the same, thereby reducing manufacturing cost and time.

The device 10 as shown is designed to be used “aftermarket” with any containers 24 the user may have provided. The device 10 may also be reused and positioned on another container 24. Again, nestable containers 24 with flat sides can be accommodated by making the device 10 flat. While larger containers 24 will of course typically have a larger radius of curvature than smaller containers the device 10 may be designed with a curvature corresponding to a large sized (5 gallon) bucket which would allow it to be effective with containers in the 1 to 5 gallon range, depending of course upon the height of the cylindrical vessel (as height affects curvature for any given volume). This is so because the device 10 is supplied with adhesive material 50 positioned on the rear face 32 of the device 10 so that a device 10 not matching the curvature of the intended container 24 will stay in position even though not perfectly flush mounted by way of adhesive 50. The adhesive 50 may be of the peel and stick type. Alternatively, the device 10 could use a suction cup arrangement or other mechanical means to ensure the device 10 remains in position, which would increase the complexity and cost of the device 10 but allow for it to be reused indefinitely. Using adhesive 50 allows for the device 10 to be reused once or twice, which is sufficient since the device 10 would be used for the life of the container 24. Of course, additional adhesive could be applied by the user in the event that the device 10 is reused, the key point being that the type of adhesive initially used is not intended to permanently fix the device 10 in position. If the radius of curvature of the device 10 is too small (i.e., the container to which it is applied has a large radius of curvature), only the laterally displaced side edges 52 of the device 10 will be in contact with the container 24 and thus the user will be instantly aware that the device 10 will not be effective for that size and shape of container 24. In accordance with a preferred use of the device 10, at least about 20% of the rear face 32 and its adhesive 50 needs to be in contact with the container 24 in order for the device to be effective. The devices 10 may also be made to exactly match the curvature of standard sized containers 24, or sold in packs having a range of curvatures. As previously mentioned, the device 10 may be made flat so that nestable containers having flat sides (i.e., having a rectangular profile as in, for example, certain wastebaskets). In this case the radius of curvature of the device 10 would be zero.

In use, the device 10 is positioned on the top edge of a nestable container 24 in the position as shown in FIG. 5. If the container 24 has a flange 27 the device 10 is positioned just under the flange 27. Otherwise, the device 10 is positioned at the top edge of the container 24 with care being taken to ensure that the upper abutment surface 20 is at least slightly below the top edge of the container 24. Adhesive 50 or other means for fixing the position of the device 10 are used to insure that the device 10 remains in the effective position as shown. Preferably a peel and stick type adhesive is used, this type of adhesive allowing for re-use of the device 10 as discussed above. The container 24 may then be nested inside the base container 24 and the process repeated for any subsequent containers 24 to be nested.

An alternative embodiment is shown in FIGS. 6A and 6B, and generally indicated by the number 100. This embodiment is configured to conform to the shape of virtually any container 24. To that end, a modified living hinge 110 is provided approximately centrally of the device 100. The hinge 110 allows the device 100 to be bent inwardly as shown with arrows 104 to effectively reduce the functional radius of curvature of the device 100. As in the prior embodiment, the device 100 comes with a predetermined radius of curvature, which radius of curvature corresponds to the radius of curvature of a standard 5 gallon bucket. The hinge 110 is formed so as to have a minimum gap space of about 1/16th of an inch. This allows for the halves 112, 114 of the device 100 to bend slightly backwards to accommodate containers with a larger radius of curvature than the device. The device 100 cannot be laid exactly flat because of the curvature of halves 112, 114, but the initial radius of curvature as described above is sufficiently large enough for a portion of the underside 118 of the device to come into contact with the surface of even a very large diameter (e.g., a standard 55 gallon drum) cylindrical container, this contact being accomplished by depressing the center 130 of the device 100 when applying it to a container 24, the center 130 having a push tab as in the prior embodiment 10. Depressing the center 130 creates a middle portion 124 of the underside of the device which can contact the sidewall of container 24. It can be appreciated that larger containers will have “flatter” sides, i.e., a large radius of curvature, larger than the radius of curvature of the device 100. At a minimum, the opposing edges 120, 122 and middle portion 124 of the device 100 must be in contact with the surface of the container 24 for proper functioning of the device 100. The middle portion 124 should be at least about 20% of the surface (underside 118) in order to be stably positioned, with the user being able to manually test for steadfastness. The device 100 can be modified to function on a flat sided container by widening the gap of the hinge 110 as shown by broken lines 118, allowing the two halves 112, 114 to be bent backwards enough for the opposing edges of the two arcuate halves to lie in the same plane, and also to create a relatively larger middle portion 124. Depressing the center 130 of the device 100 after positioning on the side of a container would allow enough of the adhesive material 132 on the underside 118 (124) of the device to come into contact with the container 24 for the device 100 to be functional. Indicia panel 134 can be conveniently used as a push tab for depressing the center 130 of the device 100. It should be noted that in this embodiment that the indicia panel 134 is split due to the formation of the hinge 110, but is still effective as in the prior embodiment. Preferably, as in the prior embodiment, a peel and stick type adhesive 132 is used to position the device 100 on the sidewall of the container. The operation of the device 100 is the same as the operation of the device 10, except that the hinge 110 allows the curvature of the device 100 to be adjusted (increased or decreased) as described above when applying it to a surface. 

1. A device for allowing the-jam free nesting of containers comprising: a substantially rectangular main body of unitary construction having upper and lower abutment surfaces, the main body formed of two hingedly attached halves and initially having a predetermined radius of curvature; a hinge formed between said two halves, said hinge formed centrally of said main body and including a gap for allowing for adjusting said radius of curvature; a lattice work of support members formed in said main body, with at least some of said support members extending from said upper to said lower abutment surfaces; a quantity of adhesive positioned on a rear surface of the device to allow the device to be removably positioned on one of said containers; whereby positioning at least one of said devices on each of said containers prevents the formation of airlock between vertically adjacent containers when vertically stacked.
 2. The device of claim 1 wherein the radius of curvature is zero.
 3. The device of claim 1 wherein the adhesive is a peel and stick type.
 4. The device of claim 1 wherein a lattice of compression reducing support members extends from a front to a rear face of the device.
 5. A method of stacking two or more nestable containers having a vertical surface comprising the steps of: providing a removable spacer device having upper and lower abutment surfaces and a central hinge said central hinge including a gap allowing for bi-directional bending of said spacer device, said spacer device having an adjustable radius of curvature, and placing said spacer device on at least one of said two containers to produce a first container with a spacing device, said first container having a predetermined radius of curvature; positioning said spacer device proximate an upper edge of the vertical surface of said first container and adjusting the radius of curvature of said spacer device to conform to said predetermined radius of curvature, and attaching the spacer device to said first container; placing the container with the spacer device within a lowermost container, and lowering said spacer device container into said lowermost container until said lower abutment surface comes into contact with said lowermost container, and; providing additional containers with spacer elements for stacking.
 6. The method of claim 5 including the step of depressing a central portion of a top side of the device to cause a central portion of a bottom side of the device to come into contact with said vertical surface. 